--- /dev/null
+package org.apache.lucene.store;
+
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import org.apache.lucene.util.BytesRef;
+
+/** @lucene.experimental */
+public final class ByteArrayDataInput extends DataInput {
+
+ private byte[] bytes;
+
+ private int pos;
+ private int limit;
+
+ public ByteArrayDataInput(byte[] bytes) {
+ reset(bytes);
+ }
+
+ public ByteArrayDataInput(byte[] bytes, int offset, int len) {
+ reset(bytes, offset, len);
+ }
+
+ public ByteArrayDataInput() {
+ reset(BytesRef.EMPTY_BYTES);
+ }
+
+ public void reset(byte[] bytes) {
+ reset(bytes, 0, bytes.length);
+ }
+
+ public int getPosition() {
+ return pos;
+ }
+
+ public void reset(byte[] bytes, int offset, int len) {
+ this.bytes = bytes;
+ pos = offset;
+ limit = offset + len;
+ }
+
+ public boolean eof() {
+ return pos == limit;
+ }
+
+ public void skipBytes(int count) {
+ pos += count;
+ assert pos <= limit;
+ }
+
+ @Override
+ public short readShort() {
+ return (short) (((bytes[pos++] & 0xFF) << 8) | (bytes[pos++] & 0xFF));
+ }
+
+ @Override
+ public int readInt() {
+ assert pos+4 <= limit;
+ return ((bytes[pos++] & 0xFF) << 24) | ((bytes[pos++] & 0xFF) << 16)
+ | ((bytes[pos++] & 0xFF) << 8) | (bytes[pos++] & 0xFF);
+ }
+
+ @Override
+ public long readLong() {
+ assert pos+8 <= limit;
+ final int i1 = ((bytes[pos++] & 0xff) << 24) | ((bytes[pos++] & 0xff) << 16) |
+ ((bytes[pos++] & 0xff) << 8) | (bytes[pos++] & 0xff);
+ final int i2 = ((bytes[pos++] & 0xff) << 24) | ((bytes[pos++] & 0xff) << 16) |
+ ((bytes[pos++] & 0xff) << 8) | (bytes[pos++] & 0xff);
+ return (((long)i1) << 32) | (i2 & 0xFFFFFFFFL);
+ }
+
+ @Override
+ public int readVInt() {
+ checkBounds();
+ byte b = bytes[pos++];
+ int i = b & 0x7F;
+ for (int shift = 7; (b & 0x80) != 0; shift += 7) {
+ checkBounds();
+ b = bytes[pos++];
+ i |= (b & 0x7F) << shift;
+ }
+ return i;
+ }
+
+ @Override
+ public long readVLong() {
+ checkBounds();
+ byte b = bytes[pos++];
+ long i = b & 0x7F;
+ for (int shift = 7; (b & 0x80) != 0; shift += 7) {
+ checkBounds();
+ b = bytes[pos++];
+ i |= (b & 0x7FL) << shift;
+ }
+ return i;
+ }
+
+ // NOTE: AIOOBE not EOF if you read too much
+ @Override
+ public byte readByte() {
+ checkBounds();
+ return bytes[pos++];
+ }
+
+ // NOTE: AIOOBE not EOF if you read too much
+ @Override
+ public void readBytes(byte[] b, int offset, int len) {
+ assert pos + len <= limit;
+ System.arraycopy(bytes, pos, b, offset, len);
+ pos += len;
+ }
+
+ private boolean checkBounds() {
+ assert pos < limit;
+ return true;
+ }
+}